VBA Code Hide rows

BrianBrucker Something along these lines should do the trick:

Sub ShowHideRows()
    Dim ws As Worksheet, i As Long
    Set ws = Application.ActiveSheet
    Application.ScreenUpdating = False
    For i = 19 To 200
        If ws.Cells(i, 11).Value Then
            ws.Rows(i).Hidden = False
        Else
            ws.Rows(i).Hidden = True
        End If
    Next i
    Application.ScreenUpdating = True
End Sub

Since the variables StartRow, EndRow and ColNum are only used once, I didn't bother defining them. By the way, column K is 11, not 10, so I changed the column number to 11 in the code above. Also, ScreenUpdating was turned off before iterating through the rows in order to improve performance.

If you have any questions, please let me know. Cheers!